To clarify not only the releasing function but the self-priming effect of gonadotropins in the anterior pituitary gland, two step administration of 100 micro-grams of synthetic LH-RH at a 60 minute interval (LH-RH two step test) was investigated in 19 women with luteal insufficiency, 7 women in puerperium (3rd-10th postpartum) and 6 women immediately after first ovulation following spontaneous abortion (pregnancy 5-7 weeks). In the luteal phase, blood samples were drawn at 0', 30', 60', 90', 120' and 180' after first LH-RH stimulation for measurement of serum LH and FSH by radioimmunoassays. delta 1 standing for hormone release = 1st peak level -0' level. delta 2 standing for selriming effect = 2nd peak level -60' level. delta 1 delta 2 ratio = delta 2/delta 1. In the luteal insufficiency group, delta 1 was significantly higher and delta 1 delta 2 ratio was lower than those in the control group. In the puerperium group, delta 1 and delta 2 responses were not detected, suggesting marked depression of the pituitary function by pregnancy. In the aborted group delta 1 and delta 2 were similar to those in the control group, indicating rapid recovery of the pituitary function. This study demonstrated that the LH-RH two step test was useful in evaluating luteal function by measuring gonadotropins.